CLIC2

Chr X

CLIC family member 2

Also known as: CLCNL2, CLIC2b, MRXS32, XAP121

This protein functions as a chloride channel that can insert into membranes and also catalyzes glutaredoxin-like reactions, while modulating ryanodine receptor 2 activity and inhibiting calcium influx. Mutations cause X-linked intellectual disability. The gene shows X-linked inheritance and is not highly constrained to loss-of-function variation.

GeneReviewsOMIMResearchSummary from RefSeq, UniProt
MultiplemechanismLOEUF 1.09
Clinical SummaryCLIC2
🧬
Gene-Disease Validity (ClinGen)
X-linked complex neurodevelopmental disorder · XLDisputed

Disputed — evidence questions this relationship

Population Constraint (gnomAD)
Low constraint (pLI 0.05) — loss-of-function variants are relatively tolerated in the population.
📋
ClinVar Variants
138 unique Pathogenic / Likely Pathogenic· 44 VUS of 241 total submissions
📖
GeneReview available — CLIC2
Authoritative clinical overview · Recommended first read
Open GeneReview ↗

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
1.09LOEUF
pLI 0.050
Z-score 1.43
OE 0.42 (0.191.09)
Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint
1.27Z-score
OE missense 0.63 (0.510.78)
58 obs / 92.4 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.42 (0.191.09)
00.351.4
Missense OE0.63 (0.510.78)
00.61.4
Synonymous OE0.97
01.21.6
LoF obs/exp: 3 / 7.1Missense obs/exp: 58 / 92.4Syn Z: 0.12
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
limitedCLIC2-related intellectual developmental disorderOTHERXLR
DN
0.6840th %ile
GOF
0.75top 25%
LOF
0.2386th %ile

This gene has evidence for multiple mechanisms of pathogenicity (gain-of-function and dominant-negative). Both the Badonyi & Marsh prediction and the broader genomic evidence point to gain-of-function as the predominant mechanism. Different variants in this gene may act through different mechanisms — interpret in context of the specific variant.

GOFprediction above median
DNprediction above median

Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.

ClinVar Variant Classifications

241 submitted variants in ClinVar

Classification Summary

Pathogenic130
Likely Pathogenic8
VUS44
Likely Benign9
Benign6
Conflicting2
130
Pathogenic
8
Likely Pathogenic
44
VUS
9
Likely Benign
6
Benign
2
Conflicting

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
0
0
130
0
130
Likely Pathogenic
0
0
8
0
8
VUS
0
28
15
1
44
Likely Benign
0
2
3
4
9
Benign
0
0
6
0
6
Conflicting
2
Total0301625199

LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly

View in ClinVar →

Protein Context — Lollipop Plot

CLIC2 · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

3D Protein StructureAlphaFold

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

Search ClinicalTrials.gov →
Clinical Literature
Open Research Assistant →